1. Field of the Invention
The present invention relates to saw blades and to means for mounting saw blades on an arbor. More specifically, the present invention relates to novel means for mounting motor driven rotary green concrete cutting blades on a driven shaft in such a manner as to prevent the substitution of blades not specifically designed for the job to be accomplished and the machine being used.
2. Description of the Prior Art
When large slabs of concrete are poured, it is necessary to provide stress grooves in the concrete while the concrete is still green. These grooves should be formed in the concrete as soon after it can be walked on without leaving footprints. When cutting such grooves, a diamond cutting blade is used which normally rotates in an up-cut direction, that is with the blade leaving the surface of the concrete with an upward movement at the leading edge of the cut. This type of cut, if not done properly, will force large particulate matter upwardly through the surface of the concrete, providing an unacceptable cut. There are some low powered light weight green concrete saws which cut a shallow groove at a low rate of speed while simultaneously supporting and troweling the surface being cut. In these machines, the cutting blade is not critical to the operation of the saw. However, in heavier, more powerful machines that can cut two inches or more deep at a speed of ten to twenty feet per minute, it is critical that the blade be matched to the machine and the aggregate in the concrete being cut. Failure to do this will result in a completely unacceptable cut, with the failure to cut the concrete properly usually being blamed on the machine instead of the blade.
Attempts have been made in the past to restrict the use of a concrete saw or the like to a particular saw blade. These attempts have included the provision of non-circular arbors on the saw and corresponding shaped mounting apertures in the saw blade. Examples of such arbors and mounting apertures may be found in U.S. Pat. Nos. 2,649,868 and 2,912,021 to Gommel, U.S. Pat. No. 3,869,795 to Treace and U.S. Pat. No. 5,303,688 to Chiuminatta. All of these examples fail to prevent the use of a wide variety of saw blades with saws having special shaped non-circular arbors. Because of the large market for concrete cutting blades, blade manufacturers refuse to be shut out any segment of that market. All that is necessary to provide a universal blade to fit any arbor is to provide a large central circular aperture in the saw blade and provide a removable mounting adapter with a mounting aperture shaped to fit a particular non-circular arbor. With this, a saw user can buy one adapter and use any type of saw blade, regardless of its' suitability for use with the saw. However, if any portion of the blade mounting aperture is closely adjacent the perimeter of the arbor, it is not possible to use an adapter to mount a different saw blade on the arbor.
With the foregoing in mind, it is an object of the present invention to provide novel mounting means for a saw blade which will insure that a blade, not specifically designed for the saw and the job to be accomplished, cannot be substituted for the required blade.
This object, and other objects of the present invention and the various features and details of the invention will be apparent from the following description of the invention.